Safety device in electrically controlled valves, fittings or the like



May 27, 1952 1 KRECAN 2,598,062

SAFETY DEVICE IN ELECTRICALLY CONTROLLED VALVES, FITTINGS OR THE LIKEFiled NOV. 16, 1948 'Amun/Kaua/c. fx1...

Patented May 27, n1952 SAFETY DEVICE IN ELECTRICALLY CON- TROLLEDVALVES, FITTINGS OR THE LIKE Jaroslav Ki'ean, Prague, Czechoslovakia,4assignor of one-half to Meopta, Consolidated Fac,- tories for Fin'eMechanical and Optical Instruments, National Corporation, Prerov,Czecho- Slovakia Application November 16, 1948, Serial No. 60,224

In Czechoslovakia November 20,1947 I 7 Claims. (Cl. 137-724) Thisinvention relates to electrically operated valves, such as thoseoperated by an associated electric motor, and more particularly, to animproved automatic control for the motor energizing circuit.

Such electric motor operated valves are widely used due to the ease withwhich they may be controlled, their relatively low cost, theirsimplicity and reliability, and their adaptability to remote control.Generally, the valves are operated by a geared motor which may rotate athreaded stem through a xed nut, or vice versa.

However, in order to insure proper closing of the valve, the stopping ofthe motor must be precisely controlled, as there is usually insufficientgive in the driving connections to take up any over travel or undertravel of the motor. l

The present invention is directed to improved torque responsive meansfor controlling the motor whereby the valve may be firmly closed andfirmly held closed independent of any precise stopping of the motor. Thetorque responsive means may also control the opening of the valve.Preferably, the invention means include one or more motor circuitcontrollers which are operated by relative movement of the motorsupportand the Valve structure when a predetermined opening or closingtorque is applied to the valve stem. The values of the torque may beselected by suitable selection or adjustment of springs controlling suchrelative movement.

In one embodiment of the invention, the driving motor is mounted on asupport movable longitudinally relative to the valve stem and biasedtoward the valve body by spring means engaging the support and anelement lsecured to the valve body. The valve stem is rotated by themotor and threaded through a nut portion on the support. The supportcarries a normally open switch included'in the valve closing circuitofthe motor, and an abutment on the fixed elementnormally holds thisswitch closed. As the valve stem meets increased resistance, when thevalve is substantially closed, the resulting reaction biases the supportoutwardly fromA the valve body, the amount of reaction to Yeffect suchmovement being determined by the spring strength. As the support movesoutwardly, the abutment releases the switch to open, breaking the motorcircuit to stop closing movement of the valve stem.

To automatically open the motor circuit during a valve 'opening'movement, a normally closed switch is imounted on .the movable supportand included` in the valve opening `motor circuit. Whereas, in the rstembodiment,fixedv abutment means limit inward movement of the support,in

the second embodiment, springs limit such movement. The spring andswitch arrangement for controlling valve closing is the same. Anabutment on the fixed element engages the normally open switch so that,when a predetermined resistance to valve opening movement is developed,the reaction through the valve stem eiects inward movement of themovable support. The last mentioned abutmentv thereupon opens thenormally closed switch to breakrthe valve opening circuit of the motor.

W'ith the foregoing inv mind, it is an object of the present inventionto provide torque responsive means controlling operation of an electricmotor operated valve. .Y

Another object is to provide torque responsive means controlling bothopening and closing movements of the valve.

These, and other objects, advantages and novel features of the presentinvention will be apparent from the following description and theaccompanying drawing. In the drawing:

Fig. 1 is a partially schematic sectional View through an electric motoroperated valve embodying the invention.

Fig. 2 is a view similar to Fig. 1 illustrating another embodiment ofthe invention.

Fig. 3 is a schematic wiring diagram illustrat-` ing a typical motor andenergizing circuits therefor, as used in the embodiment of Fig. 2.

Referring to Fig. 1, a valve body I is illustrated as having a valve 2on a rotatable stem 3 and arranged to 'cooperate with a valve seat 4,stem 3 being rotated by a geared electric motor 5. Posts 6 secured tothe valve body slidably support and guide an inner movable plate 1 xedlysecured to an outer motor supporting plate 8 by staybolts or posts 9,posts 6 having collars limiting inward movement of the movable supportformed by interconnected plates 'I and 8.

A xed element, such as a plate I0 is secured to the outer ends of posts6, and coil springs II surround the posts between plates I and I0,abutting one of these plates at each end.- vSprings II bias the movablemotor support inwardly.v Motor 5 has an elongated driving pinion I2arranged between plates 1 and I Il and meshing with a pinion I3 on theouter end' of stem 3. The stem has a threaded portion I4- extendingthrough a threaded enlargement VI5, on plate 1. One post 6 has anextension I6 extending through plate 8 and engagingY a normally openswitch I'I included'in the valve closing circuit of motor 5.

Motor is shown as having three leads, for exemplary purposes only, onelead being common and the other two each controlling opening or closingmovement of the motor, respectively. This arrangement may be used with amotor of the type having two reversely arranged elds and a commonarmature, one field controlling each direction of motor rotation.However, the motor energizing circuit is schematic or exemplary only,and the number of leads will depend on the type of reversible motoremployed.

The described arrangement operates in the following manner. When thevalve closing circuit of motor 5 is energized, stem 3 is rotated in adirection to move valve 2 toward seat 4. As the valve engages the valveseat, the resulting reaction transmitted to nut I5 by stem 3 tends tomove the support 1, 8, 9 outwardly. This outward movement is resisted bysprings II, which may be selected or adjusted to not permit such upwardmovement until a predetermined force is exerted to press valve 2 againstits seat. When such predetermined force is exceeded, movable support 1,8, 9 moves outwardly relative to xed element I9, springs II beingcompressed between plates 'I and I9. As plate 8 moves outwardly,extension I6 remains xed so that it disengages switch I'I, carried byplate 8, and this switch opens to break the valve closing circuit ofmotor 5.

' In theV arrangement of Fig. 2, an additional switch, and cooperatingtorque responsive operating means, are provided to break the valveopening circuit of motor 5 when there is a predetermined resistance toopening movement of stem 3. The means for breaking the valve closingmotor circuit is the same as in Fig. l.

l Referring to Fig. 2, the collars on posts 5 are omitted and each ofthese posts is embraced by a coil spring I8 set between valve body I andlower plate 1. Springs I8 resist inward movement of the motor support,and may be selected or adjusted to permit such inward movement only whenthe valve opening torque on valve stem 3 exceeds a preset value. Anormally closed switch I9 is provided in the valve opening circuit ofmotor 5, and is arranged to be opened by an extension 28 of the otherpost 9, extension 29 projecting through movable plate 8 into operativerelation with switch I9.

When motor 5 is energized in a valve opening direction, stem 3 rotatesthrough nut I5, the valve body and movable support remaining relativelyiixed until the torque on stem 3 exceeds a preset value, as when valve 2reaches its outer limit of movement or an obstruction to valve openingmovement is encountered. When the torque increases beyond this value,the reaction of stem 3 on nut I5 moves plate l, and attached plate 8inwardly. As extension 29 remains xed relative to the valve body, inwardmovement of plate 8 carrying switch I9 thus effects opening of switch I9by extension 29. The valve opening motor circuit is thus broken.

The valve closing control operation is the same as described for Fig. 1,as springs I8 perform the function of the collars on posts Ii (Fig. l)in limiting inward movement oi the movable motor support, except asdescribed above. The springs II act to resist outward movement of plate'l in the same manner as described.

A typical motor and control circuits, for the embodiment of Fig. 2, areshown in Fig. 3. Motor 5 is illustrated as having an armature A commonlyconnected to a valve opening eld Fo and through normally closed switchI9.

For the embodiment of Fig. 1, switchA I9 is omitted and eld Fo connecteddirectly to the corresponding contact terminal of switch CS.

While specic embodiments of the invention have been shown and describedin detail to illustrate the application of the invention principlesthereto, it should be understood that the invention may be otherwiseembodied without departf ing from such principles.

I claim:

l. An electrically operated valve assembly comprising, in combination, avalve body having a valve seat; a stem movably mounted in said body andcarrying a valve cooperable with said seat; an electrically operabledriving device operatively connected to said stem to move the latter;energizing circuitsconnected to said device to energize the latter invalve opening and valve closing' directions; an element mounted in xedrelation on said body; a support for said electric device mounted formovement inwardly and outwardly relative to said body, said supportbeing interengaged with said stern to convert the said movement by saiddriving device to movement relative to the body to open and close saidvalve and to absorb the reaction of said stem during operation of saidvalve; a normally open switch mounted on said movable support andconnected in the valve closing energizing circuit of said device; anoperator fixed to said element and arranged to engage said switch andbias the same to a closed position when said support is in its innermostposition, said operator releasing said switch to open upon outwardmovement of said support; and means associated with said element andsaid support and constructed and arranged to bias said support inwardlyrelative to said element to position said support to effect engagementof said operator with said switch to maintain said switch closed. saidmeans providing for outward movement of said support when the reactionof said stem on said support during the closing movement of said valveexceeds a preset value whereby, when said device operates said stem in avalve closing direction and the stem reaction exceeds such preset value,said support will move outwardly so that said operator will disengagesaid switch and deenergize said device.

2. An electrically operated valve assembly comprising in combination aValve body having a valve seat; astem movably mounted in said body andcarrying a valve cooperable with said seat; an electric motoroperatively connected to said stem to move the latter; energizingcircuits connected to said device to energize the latter in valveopening and valve closing directions; an element mounted in iixedrelation on said body; a support for said electric` motor mounted formovement inwardly and outwardly relative to said body; said stem beingthreadedly engaged with said support to convert the said movement bysaid electric motor to movement relative to the body to open and closesaid valve; a rst normally open switch mounted on said movable supportand connected in the valve closing energizing circuit of said motor; afirst operator aceaoea fixed to said element and arranged to engage saidswitch and bias the same to closed position when said support is in agiven position, said operator releasing said switch to open upon outwardmovement of said support from said given position; first meansassociated with said element and said support and constructed andarranged to bias said support inwardly relative to said element toposition said support to said given position to effect engagement ofsaid operator with said switch to maintain said switch closed; saidfirst means providing for outward 'movement of said support duringclosing movement of said Valve when the reaction of said stem on saidsupport exceeds a preset value; whereby, when said motor rotates saidstem in a valve closing direction and the stem reaction exceeds suchpreset value, said support will move outwardly so that said first fixedoperator will disengage said switch to open to deenergize said motor; asecond normally closed switch mounted on said support and connected inthe valve opening energizing circuit of said motor; a second operatorxed to said element and positioned wto engage and open said secondswitch when said support is in said given position; said second operatorreleasing said second switch to close when said support moves outwardlyfrom said given position, and second means associated with said elementand said support and constructed and arranged to bias said supportoutwardly relative to said element to said given position, said secondmeans providing for inward movement of said support from said givenposition when the reaction of said stem on said support during openingmovement of said valve exceeds a predetermined value; whereby, when saidmotor rotates said stem in a valve opening direction and the stemreaction exceeds such predetermined value, said support will moveinwardly so that said second ilxed operator will engage said secondswitch to open the latter to deenergize said motor.

3. A valve assembly as claimed in claim 2 in which said first meanscomprises coil springs.

4. A valve assembly as claimed in claim 2 in which said first and secondmeans comprise coil springs.

5. A valve assembly as claimed in claim 2 in which said xed element issecured on posts mounted on said body and acting as guides for saidsupport, said rst means comprises coil springs surrounding said posts;and said operator comprises an extension of one of said posts.

6. A Valve assembly as claimed in claim 2 in which said xed element issecured on posts 6 mounted on said body and acting as guides for' saidsupport, said rst and second means comprise coil springs surroundingsaid posts, and said operators comprise extensions of a pair of saidposts.

7. An electrically operated valve assembly comprising, in combination, aValve body having a valve seat; a stem movably mounted in said body andcarrying a valve cooperable with said seat; an electric motoroperatively connected to said stem to move the latter; energizingcircuits connected to said motor to energize the latter in valve openingand Valve closing directions; an element mounted in xed relation on saidbody; a support for said electric motor mounted for movement inwardlyand outwardly relative to said body, said support being interengagedwith said stem to convert the said movement by said driving device tomovement relative to the body to open and close said valve and to absorbthe reaction of said stem during operation of said valve; a normallyopen switch mounted on said movable support and connected in the valveclosing energizing circuit'of said motor; an operator xed to saidelement and arranged to engage said switch and bias the same to a closedposition when said support is in its innermost position, said operatorreleasing said switch to open upon outward movement of said support; andmeans associated with said element and said support and constructed andarranged to bias said support inwardly relative to said element toposition said support to effect engagement of said operator with saidswitch to 3 maintain said switch closed; said means providing foroutward movement of said support when the reaction of said stem onsaidsupport during closing movement of said valve exceeds a preset value;whereby, when said motor operates said stem in a valve closing directionand the stem reaction exceeds such preset value, said support will moveoutwardly so that said operator will disengage said switch anddeenergize said motor.

JAROSLAV KREAN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,681,487 Lee et al. Aug. 21,1928 FOREIGN PATENTS Number Country Date 81,383 Austria Sept. 25, 1920

